About Us
Aquila Accounting is an independent firm of accountants, registered auditors and business advisors. We support individuals and businesses with clear, practical advice across audit, accounting, tax and business consultancy.
Our Approach
No two businesses are the same. We take time to understand how you operate, what you’re working towards, and what you need from an advisor. Our focus is on straightforward guidance that helps you make confident decisions and meet your objectives.
Who we work with
We work with a wide range of clients, from small owner-managed businesses to established and growing companies across Ireland. While we support organisations across many sectors, we bring particular expertise in:
Construction
Professional services
SME-led businesses
What You Can Expect
A personal, responsive service
Clear communication and practical advice
Strong technical expertise
Long-term support as your needs evolve
Our Partners
Our people are the backbone of Aquila Accounting. Our team is made up of fully qualified professionals with specialist expertise in their respective areas. We’re chosen for being communicative, analytical and decisive, and we work closely with clients on a one-to-one basis.
Dermot O'Sullivan
Dermot was one of the founding members of the original Partnership in 1993. Prior to that he was a Tax Manager with Deloitte.
Dermot has extensive practice experience in all areas of taxation. He has particular expertise in taxation, financial and Social Welfare matters relating to Retirement and Redundancy. He also provides specialist advice on tax efficient methods of passing on the family business and other assets.
AITI — Partner
Colum McCarthy
Colum qualified as a Certified Public Accountant in 1994 and, two years later, was admitted as a member of the Institute of Taxation in Ireland. He joined the practice in 1996 and became a partner in 2006. Colum specialises in all areas of taxation and accountancy, with particular expertise in Capital Acquisitions Tax (CAT), Capital Gains Tax (CGT), all areas of Income Tax, and Relevant Contracts Tax (RCT). Known for his straightforward approach and approachable manner, Colum builds strong, lasting relationships with clients who recognise him as an effective problem solver. Since January 2022, Colum oversees the efficient day-to-day running of the practice as managing partner.
FCPA, FCA, AITI — Partner
Mervyn Good
Mervyn joined the firm in 2002 and became Partner in 2022. Mervyn is the firm’s audit and compliance partner and also specialises in the firm's consultancy assignments, particularly in the areas of business & IT consultancy. He was admitted as an associate of both Chartered Accountants Ireland and the Irish Taxation Institute in 1999. Having trained in small practice, he spent a number of years in both a "Big 4" practice and as audit manager in a medium sized practice.
FCA, AITI — PartnerOur People
Susan MacSweeney
Susan qualified as a Chartered Accountant in 2007 after training with PWC and joined the Firm that year. She deals with the Firm’s corporate and personal clients with special emphasis on the Firm’s legal client base.
FCA
Ger O’Mahony
Gerard joined the firm in 2006. He was admitted as a member of the Institute of Certified Public Accountants in 2001 and became a member of Chartered Accountants Ireland following the merger with CPA in September 2024. He deals with a mix of medium sized corporate and personal clients, with special emphasis on the firm's retail, medical and construction client base.
FCPA, FCA
Kyrle Holland
Kyrle joined the firm in 2022. He has completed successful pursuing his Chartered Accountancy qualifications while also completing his Chartered Tax Consultant exams. He deals with the firm’s corporate clients across a wide range of industries.
Kate Nowak
Kate is an IPASS-certified Payroll Specialist who brings together a genuine passion for payroll and a solid background in finance. She is dedicated to delivering a seamless, accurate and positive payroll experience for all our clients.
Khaled Ibrahim
Khaled joined the firm in 2025. He holds a Bachelor of Commerce in Accounting and Management from Mansoura University, Egypt, Awarded in 2021. He was subsequently awarded a Higher Diploma in Business from Dublin Business School in 2025. He is currently pursuing his Chartered Accountancy qualification. He deals with the firm’s corporate and personal clients, with special emphasis on its Contractors & Construction clients’ base
Bill Hanley
Bill joined the firm in 2019. He has been involved in practice accountancy for over 50 years and currently deals with a mix of self-employed and corporate clients involved in a wide range of industries.
Pat O’Donovan
Pat is a qualified Certified Public Accountant having qualified in 1998. He has extensive experience dealing with both corporate and personal businesses and deals mainly with the firm’s retail clients.
Excellence in Accounting
Delivering Integrity and Results